I forgot to mention music. (My mind must have wandered. ) Instrumental music, or even white or pink noise, can be useful when in a room with a lot of conversations going on; the sound helps drown out what they are saying, but my headphones still let me hear when something important is being announced (and I can take them off then). However, even music isn't enough for me to concentrate on reading. It adds a nice background sound, but it doesn't really use much of the brain, the way, say, jigsaw puzzles do while listening to podcasts.